1. Technical Field
The present invention relates to a biochip, a sample reaction apparatus, and a sample reaction method.
2. Related Art
In recent years, the existence of genes associated with various diseases has been revealed, and attention has been focused on the medical care utilizing genes, including genetic diagnosis, gene therapy, etc. Also in the fields of agriculture and stock raising, a number of approaches utilizing genes have been developed for breed distinction and selective breeding. Gene application techniques are thus expanding. For utilizing genes, nucleic acid amplification techniques have widely spread. As an example of such a technique, PCR (Polymerase Chain Reaction) is generally known. PCR is now an indispensable technique for elucidating the information of biological substances.
In PCR testing, a container for sample reactions, which is called a tube or a chip (biochip), is commonly used to perform the reaction. However, such an approach has problems in that a large amount of reagent or the like is required, the apparatus is complicated in order to achieve the required thermal cycle, and the reaction takes a long period of time. Therefore, there has been a demand for a biochip and a reaction apparatus for performing PCR accurately within a short period of time using very small amounts of reagent and sample.
In order to solve such a problem, JP-A-2009-136250 discloses an apparatus where a reaction liquid in the form of droplets is moved back and forth in a tube filled with a liquid (mineral oil, etc.) that is immiscible with the reaction liquid and has a lower specific gravity than the reaction liquid, thereby applying a thermal cycle to the reaction liquid to perform a reaction.
However, in the biochip described in JP-A-2009-136250, a very small amount of liquid sample has to be accurately dispensed into a plurality of chambers, so operation with skill and accuracy is required. Further, because the biochip is filled with mineral oil, some ingenuity is necessary to prevent the liquid from leaking or evaporating during storage or handling, such as the provision of a valve, a seal, etc.